Question

I am struggling retrieving a node from an XML document which has a different namespace to the rest of the document.

This is the XML:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<epp xmlns="urn:ietf:params:xml:ns:epp-1.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.nominet.org.uk/epp/xml/epp-1.0 epp-1.0.xsd">
    <response>
        <result code="1000">
            <msg>Command completed successfully</msg>
        </result>
        <resData>
            <domain:infData xmlns:domain="urn:ietf:params:xml:ns:domain-1.0" xsi:schemaLocation="urn:ietf:params:xml:ns:domain-1.0 domain-1.0.xsd">
                <domain:name>danielormisher.co.uk</domain:name>
                <domain:roid>50798439-UK</domain:roid>
                <domain:registrant>10DBFAD79B81CCDE</domain:registrant>
            </domain:infData>
        </resData>
        <extension>
            <domain-nom-ext:infData xmlns:domain-nom-ext="http://www.nominet.org.uk/epp/xml/domain-nom-ext-1.0" xsi:schemaLocation="http://www.nominet.org.uk/epp/xml/domain-nom-ext-1.0 domain-nom-ext-1.0.xsd">
                <domain-nom-ext:reg-status>Registered until expiry date.</domain-nom-ext:reg-status>
                <domain-nom-ext:auto-bill>30</domain-nom-ext:auto-bill>
            </domain-nom-ext:infData>
        </extension>
    </response>
</epp>

In the XML above, if I try to select the <domain:infData> element, which shares a namespace with the root element like so:

namespaces.AddNamespace("domain", "urn:ietf:params:xml:ns:domain-1.0");
var children = doc.SelectSingleNode("/ns:epp/ns:response/ns:resData/domain:infData", namespaces);

The node is selected fine. However, if I attempt to select the node <domain-nom-ext:infData>, which has a different namespace to the root like so:

namespaces.AddNamespace("domain", "urn:ietf:params:xml:ns:domain-1.0");
namespaces.AddNamespace("domain-nom-ext", "http://www.nominet.org.uk/epp/xml/domain-nom-ext-1.1");
children = doc.SelectSingleNode("/ns:epp/ns:response/ns:extension/domain-nom-ext:infData", namespaces);

I just get a null response. Can anyone point out what I am doing wrong??

Answer 1

Your XML sample has http://www.nominet.org.uk/epp/xml/domain-nom-ext-1.0, your code uses a slightly different namespace http://www.nominet.org.uk/epp/xml/domain-nom-ext-1.1 (i.e. 1.1 instead of 1.0. That suffices to make your code select no element as you will need to use exactly the same namespace name.